FIG. 1 shows a conventional facsimile communication system in which message data are transmitted in "point-to-point" fashion directly from an originating facsimile machine 10 to a receiving facsimile machine 12 via a public switched telephone network (PSTN) 14. In long distance facsimile communication, PSTN 14 include a message entry telephone network 16 and a message delivery telephone network 18 connected together by a public long distance telephone network 20. Message entry telephone network 16 receives data from originating facsimile machine 10, and message delivery telephone network 18 delivers data to receiving facsimile machine 12. Telephone networks 16 and 18 are typically the public switched local calling networks within which the respective facsimile machines 10 and 12 are located.
Originating facsimile machine 10 accesses receiving facsimile machine 12 by transmitting over the PSTN 14 an address signal corresponding to the telephone number of receiving facimile machine 12. The address signal and telephone number of receiving facsimile machine 12 are sometimes referred to as "destination information." The address signal is generated either by an automatic dialer included in originating facsimile machine 10 or by a facsimile machine operator manually dialing the telephone number.
Point-to-point communication between facsimile machines 10 and 12 occurs either within a single local calling network or across a long distance telephone network. Point-to-pont facsimile communication within a single local calling network is typically inexpensive. On the other hand, long distance and, in particular, international point-to-point facsimile communication can be relatively costly. The reason is that facsimile communication frequently occurs during business hours, which are typically the times when the charges for using a public long distance telepohone networks are greatest.
FIG. 2 shows a prior art facsimile store and forward network 24 that is capable of less expensive long distance facsimile communication than is the point-to-point facsimile communication described with reference to FIG. 1. Store and forward network 24 takes the place of public long distance telephone network 20 of FIG. 1 and includes an inbound node 26 and a dedicated long distance telephone communication channel or network 28 that provides long distance communication between inbound node 26 and an outbound node 30. Inbound node 26 is in the local calling area of facsimile machine 10, and outbound node 30 is preferably in the local calling area of receiving facsimile machine 12.
Store and forward network 24 is capable of providing comparatively inexpensive long distance facsimile communication because of the combined benefits of employing dedicated communication channel 28 and transmitting a substantial amount of message data via the communication channel. More specifically, a dedicated communication channel may be established between two points (e.g., inbound node 26 and outbound node 30) by, for example, leasing the channel from a telecommunication network at a fixed "wholesale" rate. Whenever a sufficient amount of message data (e.g., message data generated by multiple subscribers to store and forward network 24) are transmitted via communication channel 28, the cost per unit of message data transmitted via store and forward network 24 is less than the "retail" long distance charges associated with point-to-point communication.
Originating facsimile machine 10 cooperates with a network communication device 32 to transmit message data, destination information, and subscriber identification information to inbound node 26 via message entry telephone network 16, as will be described below in greater detail. Inbound node 26 transmits the message data and the destination information via communication channel 28 to outbound node 30, which employs the destination information to access receiving facsimile machine 12 via message delivery telephone network 18. Once communication is established between outbound node 30 and receiving facsimile machine 12, the message data are delivered to the receiving facsimile machine.
The addressing method by which originating facsimile machine 10 is interfaced with inbound node 26 differs from the addressing method employed in point-to-point communication. A first stage of the former addressing method includes the step of transmitting over message entry telephone network 16 an address signal corresponding to the telephone number of inbound node 26 to establish communication between the node and originating facsimile machine 10. A second stage of the addressing method includes the step of transmitting to inbound node 26 the subscriber identification information and the address signal corresponding to the telephone number of receiving facsimile machine 12 (i.e., the destination information).
The transmission of the subscriber identification information and destination information is typically initiated by the facsimile machine operator in response to prompts received from inbound node 26. The information is transmitted over message entry telephone network 16 either by an automatic dialer (not shown) included in network communication device 32 or by the facsimile machine operator manually entering the information with the DTMF generating touch-tone.RTM. keypad of a telephone 33 that is connected to message entry telephone network 16 with originating facsimile machine 10.
Once the addressing procedure is completed, the facsimile machine operator manually initiates transmission of the message data from originating facsimile machine 10 to inbound node 26. Originating facsimile machine 10 is operated in such a manual mode because the automatic addressing system of the facimile machine is typically incompatible with the addressing requirments of store and forward communication. The manual mode allows the facsimile machine operator to employ network communication device 32 to perform the addressing procedure without being disrupted by the addressing signals that would be generated by originating facimile machine 10 if it were operated in an automatic mode.
Most subcribers to store and forward network 24 selectively employ point-to-point facsimile communication and communication via store and forward network 24 for different facsimile transmissions. The addressing method employed in point-to-point facsimile communication includes the step of transmitting from originating facsimile machine 10 the address signal for receiving facsimile machine 12. In the two-stage addressing method of store and forward network 24, network communication device 32 or telephone 33 is used to transmit the destination information. These different operating procedures for point-to-point communication and communication via store and forward network 24 can require subscribers to change operating procedures that were established for point-to-point communication only. Moreover, facsimile machine operators would need to be trained to implement both procedures and to determine which of the two types of communication should be employed for each facsimile transmission. Such requirements are undesirable because implementation of them could be inconvenient for the subscribers to the store and forward network.